Os primeiros humanos chegaram mais cedo à América do Norte do que antes "crido" pelos cientistas

terça-feira, janeiro 17, 2017

Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada

Lauriane Bourgeon , Ariane Burke, Thomas Higham

Published: January 6, 2017

Fig 1. Cut marks on a horse mandible from Cave II.


The timing of the first entry of humans into North America is still hotly debated within the scientific community. Excavations conducted at Bluefish Caves (Yukon Territory) from 1977 to 1987 yielded a series of radiocarbon dates that led archaeologists to propose that the initial dispersal of human groups into Eastern Beringia (Alaska and the Yukon Territory) occurred during the Last Glacial Maximum (LGM). This hypothesis proved highly controversial in the absence of other sites of similar age and concerns about the stratigraphy and anthropogenic signature of the bone assemblages that yielded the dates. The weight of the available archaeological evidence suggests that the first peopling of North America occurred ca. 14,000 cal BP (calibrated years Before Present), i.e., well after the LGM. Here, we report new AMS radiocarbon dates obtained on cut-marked bone samples identified during a comprehensive taphonomic analysis of the Bluefish Caves fauna. Our results demonstrate that humans occupied the site as early as 24,000 cal BP (19,650 ± 130 14C BP). In addition to proving that Bluefish Caves is the oldest known archaeological site in North America, the results offer archaeological support for the “Beringian standstill hypothesis”, which proposes that a genetically isolated human population persisted in Beringia during the LGM and dispersed from there to North and South America during the post-LGM period.

Fig 2. Cut marks on a caribou coxal bone from Cave II.

Citation: Bourgeon L, Burke A, Higham T (2017) Earliest Human Presence in North America Dated to the Last Glacial Maximum: New Radiocarbon Dates from Bluefish Caves, Canada. PLoS ONE 12(1): e0169486. 

Editor: John P. Hart, New York State Museum, UNITED STATES

Received: September 9, 2016; Accepted: December 16, 2016; Published: January 6, 2017

Copyright: © 2017 Bourgeon et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: All relevant data are within the paper and its Supporting Information file.

Funding: Support was provided by Fonds de Recherche Québécois Société et Culture (2015-SE-179537), grant received by AB.

Competing interests: The authors have declared that no competing interests exist.